In many applications, data is sent in a serial manner from a transmitting device to a receiving device. In order to properly receive the serial data, the receiving device typically needs timing information about when each datum, symbol or bit of the serial data is to be received. In some cases, the data is transmitted with an associated clock signal which provides the timing information needed for the receiving device to properly receive the data. In other cases, the receiving device develops the associated clock signal by sensing the phase of the incoming serial data. In both cases, the associated clock signal has a frequency that is substantially constant. Because of this, relatively high energy is concentrated in substantially a single frequency, which may result in electromagnetic interference (EMI) problems. This is explained more with reference to the following example.
FIG. 1 illustrates a block diagram of a serializer/deserializer (Ser/Des) communication system 100. The Ser/Des communication system 100 includes a serializer 102 communicatively coupled to a deserializer 104. The serializer 102 typically includes a plurality of inputs to receive time-sensitive parallel data, and an input to receive a clock signal CLK1. Using the clock signal CLK1, the serializer 102 multiplexes the parallel data to generate serial data and transfers the serial data to the deserializer 104. The deserializer 104, in turn, uses another clock signal CLK2 to receive and convert the serial data back to parallel data. For proper conversion of the serial data to parallel data, the clock signal CLK2 of the deserializer 104 should cycle with substantially the same frequency as that of the clock signal CLK1 of the serializer 102.
Typically, both clock signals CLK1-2 are configured to cycle with a frequency that is substantially constant. Because of this, the energy of the clock signals as well as the data is concentrated substantially at a single frequency. This may result in the emission of electromagnetic interference (EMI) at substantially that particular frequency. This could adversely affect other components operating in proximity to the deserializer 104. Thus, there is a need to reduce EMI in such Ser/Des communication system 100.